WP_HTTP: Promote the WP_HTTP::parse_url() method to a more generic wp_parse_url() function.

Fixes #34408


git-svn-id: https://develop.svn.wordpress.org/trunk@35369 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/http-functions.php

@@ -612,3 +612,49 @@ function ms_allowed_http_request_hosts( $is_external, $host ) {
 	$queried[ $host ] = (bool) $wpdb->get_var( $wpdb->prepare( "SELECT domain FROM $wpdb->blogs WHERE domain = %s LIMIT 1", $host ) );
 	return $queried[ $host ];
 }
+
+/**
+ * A wrapper for PHP's parse_url() function that handles edgecases in < PHP 5.4.7
+ *
+ * PHP 5.4.7 expanded parse_url()'s ability to handle non-absolute url's, including
+ * schemeless and relative url's with :// in the path, this works around those
+ * limitations providing a standard output on PHP 5.2~5.4+.
+ *
+ * Error suppression is used as prior to PHP 5.3.3, an E_WARNING would be generated
+ * when URL parsing failed.
+ *
+ * @since 4.4.0
+ *
+ * @param string $url The URL to parse.
+ * @return bool|array False on failure; Array of URL components on success;
+ *                    See parse_url()'s return values.
+ */
+function wp_parse_url( $url ) {
+	$parts = @parse_url( $url );
+	if ( ! $parts ) {
+		// < PHP 5.4.7 compat, trouble with relative paths including a scheme break in the path
+		if ( '/' == $url[0] && false !== strpos( $url, '://' ) ) {
+			// Since we know it's a relative path, prefix with a scheme/host placeholder and try again
+			if ( ! $parts = @parse_url( 'placeholder://placeholder' . $url ) ) {
+				return $parts;
+			}
+			// Remove the placeholder values
+			unset( $parts['scheme'], $parts['host'] );
+		} else {
+			return $parts;
+		}
+	}
+
+	// < PHP 5.4.7 compat, doesn't detect schemeless URL's host field
+	if ( '//' == substr( $url, 0, 2 ) && ! isset( $parts['host'] ) ) {
+		$path_parts = explode( '/', substr( $parts['path'], 2 ), 2 );
+		$parts['host'] = $path_parts[0];
+		if ( isset( $path_parts[1] ) ) {
+			$parts['path'] = '/' . $path_parts[1];
+		} else {
+			unset( $parts['path'] );
+		}
+	}
+
+	return $parts;
+}